The instant invention relates to the application of dye images to various types of members, and more particularly to an apparatus for applying dye images to members utilized a sheet or sheets bearing dyes in the mirror images of the desired images, wherein the dyes are of the type which require heat for the application thereof.
Processes for applying dye images to various types of members, wherein dyes are transferred from sheets bearing the dyes in the mirror images of the desired images, are generally known in the printing art. In this regard, a process of this general type is disclosed in applicant's copending U.S. patent application Ser. No. 377,666, entitled "Method of Applying a Dye Image to a Plastic Member and the Image Bearing Member Thereby Formed". Other processes which are generally related to this art are known in the sublimation printing field. In general, processes of this type are carried out by overlying a sheet bearing dye in the miror image of the desired image on a member so that the image is in the desired orientation thereon and by thereafter simultaneously applying heat and pressure to the sheet to transfer the dye to the member so that the desired image is produced thereon.
The apparatus of the instant invention is operable for carrying out processes of this general type and comprises a bed assembly having a surface for receiving a member with a dye bearing sheet thereon, a flexible membrane which is positionable in overlying relation on the dye bearing sheet on the member and on the portion of the bed assembly surface adjacent thereto, vacuum means for drawing the membrane into pressurized communication with the sheet to effect the pressurized engagement thereof with the member, and means for heating the membrane to thereby simultaneously heat the sheet, the dye, and the member in order to transfer the dye to the member to produce the desired image thereon. In the preferred embodiment of the apparatus of the instant invention, the heating means comprises one or a plurality of radiant heating elements which emit radiant heat, preferably primarily in the infrared wavelength range, to effect heating of the flexible membrane, the dye and the member to which the dye image is to be applied. In addition, the radiant heating means is constructed so that it emits radiation towards the bed assembly surface from various angles whereby a three-dimensional member on the bed assembly surface can be heated uniformly. In this regard, preferably the radiant heating means comprises an infrared radiation emitter and a parabolic reflector which directs radiation from the emitter towards the bed assembly surface at various relative angles. Also in the preferred embodiment, the flexible membrane is preferably matched with the radiant heating means so that it is specifically absorptive to radiation within the wavelength range emitted therefrom to achieve optimum heating efficiency.
The apparatus of the instant invention is particularly effective for applying disperse dye images by plastic members in accordance with the method disclosed in the applicant's aforementioned copending U.S. patent application Ser. No. 377,666. The apparatus of the instant invention can be used for applying one or a plurality of images to a single member or for simultaneously applying a plurality of dye images to a plurality of members even though the various members have irregular printing surfaces and are three-dimensional in nature. In this regard, because the apparatus of the instant invention utilizes a flexible membrane and a means for applying a vacuum to the membrane to effect pressurized communication between a sheet and a member disposed on the bed assembly surface, a plurality of members can be positioned on the bed assembly surface, and dye images can be simultaneously applied to all of the members with one or a plurality of sheets. This is because the membrane will simultaneously conform to the configurations of all of the members and cause pressure to be applied to all of the various surfaces of the members notwithstanding some irregularities in the surface configurations thereof. In addition, it is possible to simultaneously apply dye images to two or more different surfaces of a single member with the apparatus of the instant invention. Specifically, by utilizing a dye bearing sheet having a plurality of mirror images thereon wherein the sheet is die-cut so that it can conform to the various surfaces of a single member, when the membrane is moved into pressurized communication with the member the sheet will be positioned in pressurized engagement with the different surfaces thereof so that the different images are applied to the appropriate surfaces. It should be pointed out, however, that when applying images to surfaces which are in nonparallel relation to the bed assembly surface it is important that the radiant heating means be of the type hereinabove described herein radiation is directed at the bed assembly surface from various angles so that all of the surfaces of the member are heated uniformly.
One particular use for the apparatus of the instant invention is in the application of dye images to keys of the type utilized in keyboards for typewriters, computers and the like. Specifically, the apparatus of the instant invention can be constructed so that it is adapted for simultaneously applying dye images to the keys of a fully assembled keyboard. In this regard, when the apparatus of the instant invention is constructed for printing keys on keyboards, it further comprises a frame on the bed assembly surface for receiving a fully assembled keyboard, and a skeleton plate which is receivable on the keyboard. The skeleton plate has a plurality of apertures therethrough wherein the keys are receivable to maintain the keys in substantially stationary relation while the desired images are applied thereto. A sheet having a plurality of dye images thereon, which are in the mirror images of the desired images is overlaid on the keys so that the images are in the desired orientation thereon. In the preferred embodiment, a plurality of registration pins are provided on the frame, and a plurality of apertures are provided in the sheet for receiving the registration pins to assure proper registration of the sheet relative to the keys on the keyboard. Accordingly, dye images can be simultaneously applied to all of the keys on a fully assembled keyboard by positioning a dye bearing sheet over the keys as hereinabove set forth, placing the membrane over the keyboard, evacuating the membrane so that it is drawn into pressurized communication with the keys, and thereafter applying heat to the membrane. Hence, a keyboard can be fully assembled with blank keys, and thereafter the keys on the fully assembled keyboard can be imprinted with the desired images utilizing the apparatus of the instant invention As a result, keyboards which heretofore had to be manually assembled in order to assure that each different key was assembled in the proper location can now be robotically assembled with blank keys, and thereafter the keys can be imprinted with the desired images. Therefore it is seen that a substantial savings in labor costs can be realized with the apparatus of the instant invention, particularly when it is used for applying images to keys of a keyboard.
Accordingly, it is a primary object of the instant invention to provide an apparatus for applying a dye image to a member utilizing a sheet bearing a dye in the mirror of said image, the dye being of the type requiring heat for the application thereof and having a melting point which is below the melting point of the material comprising the member.
Another object of the instant invention is to provide an effective apparatus for practicing the method disclosed in applicant's copending U.S. patent application Ser. No. 377,666.
A further object of the instant invention is to provide an apparatus for simultaneously applying dye images to a plurality of surfaces of a three-dimensional member.
An even further object of the instant invention is to provide an apparatus for simultaneously applying dye images to a plurality of keys assembled on a keyboard.
Still another object of the instant invention is to provide an apparatus for applying a dye image to a plastic member wherein a dye bearing sheet is first overlaid on the member, a flexible membrane is overlaid on the sheet, and vacuum is applied to the membrane to effect the pressurized engagement of the dye bearing sheet with the member and wherein thereafter radiation is directed toward the sheet to effect the heating of the dye and the member so that the image is transferred to the member.
Other objects, features and advantages of the invention shall become apparent as the description thereof proceeds when considered in connection with the accompanying illustrative drawings.